Tovstyj Lis, just 11 kilometers away, was one of the worst-hit areas. It was evacuated within weeks and became part of the exclusion zone that now surrounds the crippled nuclear reactor.

Olha Bolyura was born in Tovstyj Lis.

Of the 3,000 people who lived in the village before the accident, she says only a handful are still alive.

"There are almost no people left. All the drivers have died, all the builders have died. These were young people, and now just a few are left," she says. "Somehow it's the young people who died first. The elderly are still alive."

'All Because Of Chornobyl'

When the reactor exploded, Bolyura, who was then 32 years old, lived in Kyiv with her husband and their young son. But the rest of her family lived in Tovstyj Lis or in neighboring towns and was exposed to massive doses of radiation.

Bolyura's father died one year after the Chornobyl explosion. Her brother, who helped clean up the contaminated wreckage, died four years ago after suffering a brain tumor and three strokes.

Her other relatives are all battling serious health conditions that Bolyura blames on radiation.

Bolyura's niece Natalya, who was a healthy teenager at the time of the accident, is the most severely disabled.

"She cannot walk. She is blind. She is an invalid of the first category," she says. "It's awful to see her suffering. She drags herself through the house on her backside. Her legs have given out; her arms are weak. This is all because of Chornobyl."

The sarcophagus covering the damaged fourth reactor at the Chornobyl nuclear power plant is seen behind a building decorated with graffiti in the abandoned city of Prypiat.

Natalya is the only member of the family to receive compensation from the state in the form of a monthly invalidity pension that is barely enough to cover her basic needs.

Like many in Ukraine and Belarus, Bolyura resents the Soviet government for initially covering up the disaster. Now, 25 years later, she says authorities are deliberately playing down its long-term health effects.

Imprisoned For Criticism?

Yury Bandazhevsky is a medical pathologist who was the first expert in Belarus to study the consequences of the Chornobyl disaster.

While head of the Gomel Medical Institute -- located in one of the cities worst affected by the meltdown -- Bandazhevsky chronicled a growing incidence of cancer and other afflictions in the wake of Chornobyl. He criticized Soviet authorities for their failure to respond urgently to the crisis by providing quick supplies of substances like potassium iodide, which can prevent the absorption of radioactive iodine into the thyroid.

Bandazhevsky was imprisoned by Belarusian authorities in a case that international watchdogs like Amnesty International believe was tied to his openly critical stance. After his release, Bandazhevsky left Belarus and now works in France and Ukraine.

An ardent opponent of nuclear power, he tells RFE/RL's Belarus Service that authorities in Minsk even today continue to disregard the massive health crisis caused by the disaster. He says fallout from Japan's Fukushima reactor, damaged in last month's earthquake and tsunami, as well as plans to construct a new Russian-built reactor in Belarus, will only exacerbate illnesses in people whose health has already been compromised by radiation from Chornobyl.

"Several generations already have been exposed to large doses of radiation, and the result is the poor state of health that we're now seeing," he says. "Cardiovascular disease and cancer -- all this is a consequence. And any additional doses [of radiation], even small ones, will cause people's health to deteriorate further because they're already in poor health, with lowered immunity and metabolic problems. So to receive additional radiation on top of that is highly undesirable."

The health effects of the Chornobyl disaster have long been subject to debate. But researchers generally agree that the incidence of thyroid cancer, particularly among children, increased thirtyfold after 1986.

Tens of thousands of cases have since been reported, as have rises in the incidence of breast cancer, intestinal cancer, cancer of the bladder, lung cancer, and gastric cancer. The risk of leukemia in children in the contamination zones is three times higher than elsewhere.

Blame It On Chornobyl

Disorganized research standards in Belarus, Ukraine, and Russia have meant that not all health effects of Chornobyl were measurable. And that, say researchers like Ukrainian psychiatrist Semyon Hluzman, has caused a knock-on psychological effect -- the sense among many survivors that all ailments are tied, in one way or another, to Chornobyl.

"It's interesting to observe that today, people who were born into an independent Ukraine, or people who have long since forgotten about Chornobyl and are living their nice Kyiv lives -- all the same, these people almost all say that their poor health is a result of the Chornobyl disaster," Hluzman says. "This isn't a problem of Chornobyl. It's a problem of lack of trust in medical practitioners, in Ukrainian medical science."

Such self-diagnoses have led Chornobyl to play a disproportionate role in authorities' thinking on health-care matters. Johan Havenaar, a Dutch psychiatrist who has conducted numerous studies in Belarus and Ukraine since 1990, has consistently found lower incidence of psychological illnesses among Chornobyl survivors than studies done by local doctors.

Belarusian state employees plant trees on contaminated land near the abandoned village of Bogushi.

Havenaar, who currently works with the Altrecht Institute for Mental Health, chalks up the discrepancy to poor epidemiological standards in Belarus and Ukraine and a willingness among some researchers to blame Chornobyl for all of society's ills.

At the same time, however, he says the Chornobyl accident -- which came just years before the Soviet collapse -- undoubtedly left deep psychological scars on those it affected, particularly the 400,000 people who were forced to evacuate their homes.

"All these people really have lost a lot of trust in their environment," Havenaar says. "They're confused by all the contradictory reports; they don't understand why some people are receiving examinations every year while they are living in almost the same conditions and they're not getting anything. Many people had to be evacuated. [The disaster also] had an enormous impact on the economy, which was already going down when the Soviet Union was falling apart. So this disaster had an enormous societal impact."

History Repeating Itself

Japan's Fukushima disaster has served as an eerily appropriate backdrop to the Chornobyl anniversary, with the world once again fixated on the dangers of nuclear power. Many Chornobyl experts say Japan is better equipped to deal with its nuclear crisis because of strong community support systems and a more transparent government.

But the government of Japan, like that of the former Soviet Union, has come under criticism for failing to accurately assess the severity and scope of its own meltdown. Bandazhevsky says Japanese authorities are poised to preside over their own unfolding health disaster -- and are turning a blind eye to the true scale of the problem, just as authorities did a quarter-century ago with Chornobyl.

"The situation is being repeated," he says. "Twenty-five years ago we were hearing the same things about the Chornobyl disaster -- that there was no problem, that Chornobyl was safe. They really said almost nothing at all the first week. And then we found ourselves faced with a terrible nightmare."RFE/RL's Belarus and Ukrainian services contributed to this report